Cargo sling

ABSTRACT

A cargo sling which maintains stability on releasing any one of a number of loads being carried thereby. The sling is releasably connected to a supporting structure for releasing the loads collectively, and includes a supporting ring or equivalent thereof for supporting a plurality of cargo hooks. Each hook is preferably operable automatically, and is connected substantially unyieldingly to the supporting structure by means of an interconnected plurality of suspension arms and a corresponding plurality of sling arms. Such arms are completely interchangeable and, under load, assume a conical configuration wherein the centre of gravity is located so as to assure stability of the load during any vertical, transverse or translational motion of the cargo sling and load. The cargo sling is particularly adapted for use with helicopters.

o v United States Patent 1151 3,656,796 Cook [451 Apr. 18, 1972 [54]CARGO SLING 994,668 7/1911 Sevin and Roussel ..294/75 [72] Inventor:Lionel H. J. Cook, Vancouver British 3,341,244 9/1967 .Iohnson ..294/75Columbia, Canada Primary Examiner-Richard E. Aegerter [73] Asslgnee'ggggz g f z g gg fi Vancouver Assistant Examiner-Douglas D. WattsAtromey-Cushman, Darby & Cushman [22] Filed: July 13,1970 i 7 211 Appl.N6; 64,004 57 ABSTRACT R l d [15, Application D I A cargoJ sling Fire];maggtains staoilgty an reeasinianysne of a num er 0 0a s mg came ere y.e s mg is [63] Commuatlo" of 737,782 June 171 1968* releasably connectedto a supporting structure for releasing abandonedthedgildstclollectfivtely, and l itr icludesl a lstippct rting ring kor equ1v en tereo or suppo mga pura1yo cargo 00 s. [30] Poms Apphcauon Pmriy DataEach hook is preferablyoperable automatically, and is con- Aug. 24, 1967Canada ..998 610 nected substamlally y s y to the supportms Structure bymeans of an interconnected plurality of suspension arms [52] U.S.Cl...294/78 R, 294/74, 294/87 n a e p n ng pl y of i g m h arms are 51 Int.Cl ..B66c 1/34 completely Interchangeable under load, assume a co [58]Field of Search ..294/78, 81,81 SF, 74, 75, configuration wherein thecentre of gravity is located so as to I 294/82 AN, 87, 78, 66 assurestability of the load during any vertical, transverse or translationalmotion of the cargo sling and load. The cargo 56] References Cited slingis particularly adapted for use with helicopters. l

UNITED STATES PATENTS 1,060,696 5/ 1913 Naucler ..294/8l 2 Claims, 6Drawing Figures CARGO SLING This is a continuation of my previouslyfiled application serial number 737,782, filed June 17, 1968, nowabandoned.

This invention relates generally to a cargo sling which is adapted to becarried in suspension from a supporting member. Specifically, thepresent invention provides for a cargo sling which may be carried by acargo hook mounted on an overhead crane, a boom assembly, and inparticular, as adapted to be mounted on an aircraft fuselage.

i A common problem encountered when a loador plurality of loads iscarried by a cargo sling, is that of maintaining stability following therelease of one of such loads. It will be evident, of course, that theneed for maintaining proper stability upon the release of a load isparticularly acute when the load is carried from the fuselage of ahelicopter, or similar type of hovering aircraft. It will be evenmoreevident that the problem of maintainingstability as between the cargosling and the helicopter carrying such a sling, is particularlyimportant under those conditions where a number of loads (identical, orotherwise) are being carried simultaneously, but are to be releasedseparately. Such loads might be in the form of a number of fuel drums,or other types of pre packaged or self-contained supply caches.

Inasmuch as cargo slings are to be used to transport loads of the typedescribed above by air into remote areas which are often "otherwiseinaccessible, it is desirable to be able to release either a selectedone of a plurality of individual loads being carried by the cargo sling,or the entire cargo sling with all of the loads.

It is,'-accordingly, an object of the present invention to provide acargo sling which has improved characteristics of stability upon releaseof a load therefrom.

, It is another object of the present invention to provide a cargo slingwhereby a plurality of loads may be carried, such loads to be releasedeither individually or collectively.

These and other objects and features of the present invention may befound in a cargo sling which is adaptedto be suspended from a supportingmember for carrying a load or a plurality of loads, said cargo slingcomprising; one support frame in the form of a closed loop that isadapted to carry a plurality of cargo hooks thereon, each cargo hookhaving a minimum rated capacity at least equal to its particular load; aplurality of sling arms each of substantially the same length and eachhaving one end thereof attached to the support frame; and a plurality ofsuspension cable means one end of each cable means being attachable tosaid supporting member, with the other end of each of the cable meansbeing attached to the other end of associated ones of the sling arms.Preferably, the sling arms will be releasably attached to the supportframe at points which are spaced equidistant apart along the closedloop. Moreover, each of the sling arms is preferably identical inconstruction, and each of the suspension cable means is preferablyidentical in construction.

' In a particular embodiment of this invention, the present cargo slingis adapted to be suspended from the fuselage of a helicopter.Preferably, the suspension cable means are connected to a swivelingbridle which is itself releasably attachable to the helicopter fuselage.In yet another preferred embodiment, the present invention provides acargo sling as above described, utilizing therewith a cargo hookassembly of the type disclosed in our co-pending patent application,filed concurrently herewith and having the Ser. No. 737,783.

With reference to the drawings which illustrate a preferred embodimentof the present invention;

FIG. 1 is an elevation view, showing pictorially a cargo sling beingsuspended from the fuselage of a helicopter;

FIG. 6 is an elevation view, partly in section, taken along line 6-6 ofFIG. 5.

FIG. 1 shows a cargo sling 10 suspended by means of a support bridle 12from a cargo hook 50 conventionally supported on the underside of afuselage 52 of a helicopter. The cargo hook 50 may be on any knownconstruction, but'preferably is an automatically releasing type of cargohook. That is, the cargo hook 50 may be actuated remotely to release itsload. Furthermore, the cargo hook 50 may be specifically of the typeshown and disclosed in our co-pending patent application mentionedabove. Further yet, the cargo hook 50 will normally be pivotally orotherwise movably connected to the fuselage 52 of the helicopter, inorder to provide for some degree of relative motion therebetween.However, it is not intended that the cargo hook 50 be limited to such aconstruction.

A plurality of suspension means shown here in the form of suspensioncables 14 are provided with closed loops l6 suitable formed at eitherend of the suspension cables, such loops l6 facilitating the attachmentof the suspension cables 14 to the support bridle 12. See FIG. 2. Thesupport bridle 12 is provided with an elongated slot 11, through whichthe hook member of the cargo hook 50 extends to support the bridle. Atthe end of the support bridle 12, remote from, the slot 11, there isprovided a plurality of extensions 13 which define a correspondingplurality of slots 13a. Each of the extensions 13 has a bore holeextending transversely therethrough, for receiving bolt means or similarfastening means used to connect-the suspension cables 14 to the supportbridle 12.

Each of the Loops 16 has a shackle 18 connected thereto at the end ofeach of the suspension cables 14 remote from the support bridle 12, fordetachably connecting the sling arms 20 to the suspension cables 14.Alternative and equivalent structure could also be used instead of theshackles 18. Each of the sling arms 20 is provided at each end thereofwith closed loops 20a, substantially similar in construction to theloops 16 of the suspension cables 14. A second set of shackles 22,substantially identical to the shackles 18, are provided to detachablyconnect the sling arms 20 to a generally circular support ring 24 in theform of a closed loop. Although the support ring 24 is shown to besubstantially circular both in cross-section, and

in plan view, it may of course be of other equivalent form,

such as a spoke-like arrangement.

Spaced along the length of the support ring 24 are a first plurality ofring supports 26, and mounted on the support ring 24 on either side ofeach such ring support 26, are a second plurality of hook supports 28.The rings supports-26 and the hook supports 28 are substantiallyidentical .in construction, differing only by the extent to which suchsupport have been tightened by means of suitable fastening means, in theform of bolts or the like, when the supports have been connected to thesupport ring 24. See FIGS. 4 and 6. Each of the supports 26 and 28 is inthe form of an elongated plate, which has been formed by bending or thelike to a loop portion 26a, and 28a, respectively, and tongue portions26b and 28b, respectively. Each of the tongue portions 26b and'28b isprovided with a bore hole 27 and 29, respectively, for receivingfastening means connecting such supports either to the sling arms 20, orto each of a plurality of cargo hooks 30 of the cargo sling 10. FIGS. 4and 6 show fastening means in the form of a bolt 31, for securing therings supports 26 and the hook supports 28, suitably apertured, to thesupport ring 24 to prevent any relative motion therebetween. Inaddition, the tongue sections 26b and 28b of the ring supports 26 andthe hook supports 28 are also provided with suitable fastening meansinthe form of bolts or the like, for tightening together of the respectivetongue sections of such supports, for clamping the same to the supportring 24.

It is to be noted that in the embodiment described herein, the ringsupports 26 and hook supports 28 are spaced apart substantially by anequal distance, for providing better dis-.

tribution of the weight of any load being carried by the cargo hooks 30.In addition, it will be noted from FIG. 3 that each of the ring supports26 is positioned approximately mid-way I cargo hook 50 on the helicopter52. In other words, the

suspension cables 14, and the sling arm 20 and the support ring 24 areso interconnected as to be essentially unaffected with respect tostability by the release of a selected one of the loads from a cargohook 30. As in the case of the cargo hook 50, the cargo hooks 30 mountedon the support ring 24, may be of any knownconstruction. However, thetype of cargo hook disclosed in our above-mentioned co-pending patentapplication is particularly well suited for use with the present cargosling 10. It should be noted, of course, that the cargo hooks 50 and 30may be electrically operated, in which case conductor means must beprovided to effect electrical interconnection between an electricalpower supply being carried by the helicopter, and the cargo hooks 30being carried by the support ring 24. Such electrical conductor meanswill include quick release connections, for providing rapiddisconnection of the electrical circuitry in the event that the entirecargo sling l and its load,--is to be simultaneously dropped byreleasing the cargo hook 50.

In general terms, each of the suspension cables 14, as well as each ofthe sling arms 20, will be manufactured from a material whose strengthproperties are compatible with the weight of load being contemplated fortransport using the cargo sling 10. However, each of the suspensioncables 14, as well as each of the sling arms will, in fact, beconstructed to incorporate safety factors therein, which, in effect,will result in a considerable overload capability being built'into thecargo sling l0.

From the symmetrical arrangement employed in constructing the cargosling 10 shown herein, it can be seen that positioning of the supportring 24 will always be maintained in a generally horizontal attitude,irrespective of which one, or several, of the plurality of cargo hooks30 is carrying a load. In addition, it may be seen that following thepick-up of the loads by each of the cargo hooks 30, that any one of suchloads may be released individually, without affecting the stability ofthe cargo sling 10. This feature is particularly important since thecargo sling 10 is supported from a helicopter, which, as it.

hovers over a location where a load is to be released or set down, willbe inherently unstable to' a certain degree. That is to say, thehelicopter is unstable itself to a certain degree, and, therefore, it ishighly desirable that releasing of one or more of the loads eithersimultaneously or separately, should not further contribute to therelative instability of the helicopter.

Accordingly, the cargo sling 10 as it is supported by the cargo hook 50on the helicopter, will, in fact, be substantially stable,

being unaffected by the manner in which the loads are released from thecargo hooks 30.

it can also-be seen from the description and drawings of the presentcargo sling 10, that each of the suspension cables 14, as well as eachof the sling arms 20, may be interchanged end for end without affectingthe operation of the cargo sling. That is to say, any one of thesuspension cables 14 may be interchanged with another of the suspensioncables, and each of the cargo slings may be interchanged in a similarmanner. Further yet, the structure of each of the ring supports 26 andeach of the hook supports 28 are generally similar to the extent thatsuch supports may also be interchanged, or substituted one for theother, if it is so required.

Although it has not been shown in FIG. 1 of the present drawings, thecargo hook 50 is usually connected to the fuselage 52 of the helicopterby means of a swivel joint. Such a swivel joint is desirable in order toprevent entanglement or twisting of the cables due to aerodynamic forceson the loads being carried. If desired, the swivel joint may be aninherent part of the main cargo hook connected to the aircraftsfuselage, or alternatively, it may be separate from the main cargo hook.in addition, the swivel joint is designed to carry the same full load ascarried by the cargo hook. The swivel oint IS completely sealed andelectrical contacts in the fonn of copper strips are mounted within theswivel joint. The copper strips are mounted in a fixed, two part blockwithin the swivel joint in order to maintain continuity of an electricalpath in the event of possible failure of either copper strip. Preventingtwisting or tangling of the cables of the cargo sling is desirable sincethe cables could wind up, in the absence of a swivel joint, to such anextent that the eye of the cable will be jammed against the body of thecargo hook and stop releasing of the load.

I claim:

1. A cargo sling adapted to be suspended from a supporting member, suchas an airborne vehicle fuselage, for carrying at least one load, saidcargo sling comprising:

a support frame in the formof a unitary closed loop disposed generallyhorizontally;

a plurality of cargo hooks mounted on said support frame at angularlyspaced sites;

a plurality of sling arms, each having two ends and all of said slingarms being of substantially the same length, the number of sling armsequalling the number of cargo hooks;

a plurality of suspension cables, each having two ends and all of saidsuspension cables being of substantially the same length;

a plurality of shackles equalling in number the number of saidsuspension cables;

a bridle having means thereon for securing the bridle to the supportingmember;

means securing one upper end of each suspension cable to said bridle;

means securing the opposite, lower end of each suspension cable to arespective one shackle of said plurality of shackles;

means securing each one upper end of each sling arm to a respective oneshackle of said plurality of shackles in an evenly distributed fashionsuch that each said shackle has an equal number of sling arm one upperends secured thereto;

means securing the opposite, lower end of each sling am to said unitary,closed loop, support frame at a respective one of said sites, wherebysaid sling arms are connected to said support frame at all saidangularly spaced sites;

said suspension cables and said sling arms being of fixed length andplurality of cargo hooks being constructed for operation independentlyof one another and independently of said suspension cables and saidsling arms for grasping and releasing loads.

2. The cargo sling of claim 1 wherein:

each sling arm is constituted by a cable having means defining a closedloop at each end thereof for constituting the two recited securing meansthereof;

each suspension cable is constitued by a cable having means defining aclosed loop at each end thereof for constituting the two recitedsecuring means thereof; and

there are at least twice as many sling arms as there are suspensioncables.

101012 Inn

1. A cargo sling adapted to be suspended from a supporting member, suchas an airborne vehicle fuselage, for carrying at least one load, saidcargo sling comprising: a support frame in the form of a unitary closedloop disposed generally horizontally; a plurality of cargo hooks mountedon said support frame at angularly spaced sites; a plurality of slingarms, each having two ends and all of said sling arms being ofsubstantially the same length, the number of sling arms equalling thenumber of cargo hooks; a plurality of suspension cables, each having twoends and all of said suspension cables being of substantially the samelength; a plurality of shackles equalling in number the number of saidsuspension cables; a bridle having means thereon for securing the bridleto the supporting member; means securing one upper end of eachsuspension cable to said bridle; means securing the opposite, lower endof each susPension cable to a respective one shackle of said pluralityof shackles; means securing each one upper end of each sling arm to arespective one shackle of said plurality of shackles in an evenlydistributed fashion such that each said shackle has an equal number ofsling arm one upper ends secured thereto; means securing the opposite,lower end of each sling arm to said unitary, closed loop, support frameat a respective one of said sites, whereby said sling arms are connectedto said support frame at all said angularly spaced sites; saidsuspension cables and said sling arms being of fixed length andplurality of cargo hooks being constructed for operation independentlyof one another and independently of said suspension cables and saidsling arms for grasping and releasing loads.
 2. The cargo sling of claim1 wherein: each sling arm is constituted by a cable having meansdefining a closed loop at each end thereof for constituting the tworecited securing means thereof; each suspension cable is constitued by acable having means defining a closed loop at each end thereof forconstituting the two recited securing means thereof; and there are atleast twice as many sling arms as there are suspension cables.